Apparatus and method for background noise estimation with a binaural hearing device supply

Abstract

An apparatus and a method for background noise estimation use a first and a second hearing device for binaural supply of a hearing impaired person. In each case the hearing devices have a first and a second omnidirectional microphone and the two microphones of each hearing device are connected to each other electrically in order to form a first and/or a second monaural directional characteristic. The first and/or second microphone of the first hearing device is connected together wirelessly with the first and/or second microphone of the second hearing device to form a binaural directional characteristic. To estimate the background noise, the level of an output signal from the first and/or the second directional microphone having a monaural directional characteristic is combined with the level of an output signal from the directional microphone having a binaural directional characteristic. Background noise estimation is thereby enhanced in the case of binaural supply.

The invention claimed is: 
     
       1. An apparatus for background noise estimation, the apparatus comprising:
 first and second hearing devices for binaural supply of a hearing impaired person, each of said hearing devices having a first and a second omnidirectional microphone and said first and second microphones of each of said hearing devices connected to each other electrically to form a first and a second directional microphone having a first and a second monaural directional characteristic respectively, one of said first and second microphones of said first hearing device connected together wirelessly with one of said first and second microphones of said second hearing device to form a directional microphone having a binaural directional characteristic, and for estimating background noise, levels of output signals from said first and second directional microphones having the monaural directional characteristic are combined with a level of an output signal from said directional microphone having the binaural directional characteristic; 
 wherein the binaural directional characteristic and at least one of the first and the second monaural directional characteristic form a zero point in a direction of a useful sound source. 
 
     
     
       2. The apparatus according to  claim 1 , wherein at least one of the first and the second monaural directional characteristic forms a monaural anti-cardioid. 
     
     
       3. The apparatus according to  claim 1 , wherein the binaural directional characteristic forms a binaural figure of eight. 
     
     
       4. The apparatus according to  claim 1 , wherein the background noise is formed by forming a maxima of the levels of the output signals from the directional microphones. 
     
     
       5. The apparatus according to  claim 1 , wherein the background noise is formed by forming sums of the levels of the output signals from the directional microphones. 
     
     
       6. An apparatus for background noise estimation, the apparatus comprising:
 first and second hearing devices for a binaural supply of a hearing impaired person, said first hearing device having a first omnidirectional microphone and said second hearing device having a first and a second omnidirectional microphone and said first and second omnidirectional microphones of said second hearing device are electrically connected to each other to form a second directional microphone having a monaural directional characteristic, said first microphone of said first hearing device connected together wirelessly with one of said first and second microphones of said second hearing device for forming a directional microphone having a binaural directional characteristic, and for estimating a background noise, a level of an output signal from said second directional microphone having the monaural directional characteristic is combined with a level of an output signal from the directional microphone having the binaural directional characteristic; 
 wherein the combined binaural directional characteristic and monaural directional characteristic form a zero point in a direction of a useful sound source. 
 
     
     
       7. The apparatus according to  claim 6 , wherein the monaural directional characteristic forms a monaural anti-cardioid. 
     
     
       8. The apparatus according to  claim 6 , wherein the binaural directional characteristic forms a binaural figure of eight. 
     
     
       9. The apparatus according to  claim 6 , wherein the background noise is formed by forming a maxima of the levels of the output signals from the directional microphones. 
     
     
       10. The apparatus according to  claim 6 , wherein the background noise is formed by forming sums of the levels of the output signals from the directional microphones. 
     
     
       11. A method for background noise estimation, which comprises the steps of:
 providing a first and a second hearing device for a binaural supply of a hearing impaired person, in each case the first and second hearing devices have a first and a second omnidirectional microphone and the first and second microphones of each of the hearing devices are connected to each other electrically for forming a first and a second monaural directional characteristic; 
 connecting one of the first and second microphones of the first hearing device together wirelessly with one of the first and second microphones of the second hearing device for forming a binaural directional characteristic; and 
 estimating a background noise by combining levels of output signals from the first and the second directional microphone having the monaural directional characteristic with a level of an output signal from the directional microphone having the binaural directional characteristic, the combined binaural directional characteristic and monaural directional characteristic forming a zero point in a direction of a useful sound source. 
 
     
     
       12. The method according to  claim 11 , which further comprises forming the background noise by forming a maxima of the levels of the output signals from the directional microphones. 
     
     
       13. The method according to  claim 11 , which further comprises forming the background noise by forming sums of the levels of the output signals from the directional microphones. 
     
     
       14. A method for background noise estimation, which comprises the steps of:
 providing a first and a second hearing device for binaural supply of a hearing impaired person, the first hearing device having a first omnidirectional microphone and the second hearing device having a first and a second omnidirectional microphone and the first and second microphones of the second hearing device are electrically connected to each other for forming a second monaural directional characteristic; 
 connecting the first microphone of the first hearing device together wirelessly with one of the first and second microphones of the second hearing device for forming a binaural directional characteristic; and 
 estimating a background noise by combining a level of an output signal from the second directional microphone having a monaural directional characteristic with a level of an output signal from the directional microphone having the binaural directional characteristic, the combined binaural directional characteristic and monaural directional characteristic forming a zero point in a direction of a useful sound source. 
 
     
     
       15. The method according to  claim 14 , which further comprises forming the background noise by forming a maxima of the levels of the output signals from the directional microphones. 
     
     
       16. The method according to  claim 14 , which further comprises forming the background noise by forming sums of the levels of the output signals from the directional microphones.